Re: [Boost-users] [fusion][mpl][array] making boost array a conforming mpl sequence (through fusion)

Subject: Re: [Boost-users] [fusion][mpl][array] making boost array a conforming mpl sequence (through fusion)
From: Stjepan Rajko (stjepan.rajko_at_[hidden])
Date: 2009-02-12 18:45:49

On Thu, Feb 12, 2009 at 10:12 AM, Stjepan Rajko <stjepan.rajko_at_[hidden]> wrote:
>
> I was able to get the fusion-adapted boost::array to be a conforming
> mpl sequence by adding:
>
> namespace boost { namespace mpl {
>
> template<typename T, std::size_t N>
> struct tag<boost::array<T,N> >
> {
>    typedef boost::fusion::fusion_sequence_tag type;
> };
>
> template<typename T, std::size_t N>
> struct sequence_tag<boost::array<T,N> >
> {
>    typedef boost::fusion::fusion_sequence_tag type;
> };
>
> }}
>
>

Furthermore, I am able to execute a transform on the array after adding this:
http://pastebin.com/f40b33e1d

This works perfectly, that is, minus the fact that adding it in gives
me some really bizarre compilation errors (gcc 4.0.1, darwin):

/Development/boost/boost/fusion/adapted/array/array_iterator.hpp: In
instantiation of
'boost::fusion::array_iterator<boost::array<ame::patterns::normal_model_state,
12ul>, 0>':

...

/Development/boost/boost/fusion/adapted/array/array_iterator.hpp:29:
error: 'boost::array<ame::patterns::normal_model_state,
12ul>::<anonymous enum>' is/uses anonymous type
/Development/boost/boost/fusion/adapted/array/array_iterator.hpp:29:
error:   trying to instantiate 'template<class Seq1, class Seq2>
struct boost::fusion::detail::enable_comparison'

The offending line in array_iterator is:
BOOST_MPL_ASSERT_RELATION(Pos, <=, Array::static_size);

Commenting out that line results in a successful compile, and the
program runs as expected.

I would really appreciate it if someone could help me out here, I am
in total dark as to why the BOOST_MPL_ASSERT_RELATION is not working
correctly, and what fusion::detail::enable_comparison has to do with
anything.

TIA,
Stjepan